Sir Ernest Alexander Campbell MacMillan, (August 18, 1893 – May 6, 1973) was a Canadian orchestral conductor, composer, organist, and Canada's only "Musical Knight".He is widely regarded as being Canada's pre-eminent musician, from the 1920s through the 1950s.His contributions to the development of music in Canada were sustained and varied, as conductor, performer, composer, administrator, lecturer, adjudicator, writer, humourist, and statesman.